> ## Documentation Index
> Fetch the complete documentation index at: https://docs.uniblock.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Ankr

> Connect to Ankr streams through Uniblock WebSockets.

Ankr WebSockets are available through Uniblock with a validation endpoint and a
matching WSS endpoint.

## Endpoints

* WebSocket (WSS): `wss://websocket.uniblock.dev/ankr?chainId=1`
* HTTP (Validation): `https://websocket.uniblock.dev/ankr/validate?chainId=1`

## Required parameters

* `chainId` is required.
* Include the `X-API-KEY` header in both validation and connection requests.

## Workflow

1. Validate the request with the HTTP endpoint.
2. Connect to the WSS endpoint using the same `chainId`.
3. Send your Ankr WebSocket subscription message.

## Example validation request

```bash theme={null}
curl --request GET \
  --url 'https://websocket.uniblock.dev/ankr/validate?chainId=1' \
  --header 'X-API-KEY: YOUR_UNIBLOCK_API_KEY'
```

## Pricing

Ankr WebSocket usage is billed per active subscription and per notification
received, split by EVM and non-EVM chains:

* Subscription (EVM): 416.67 CUs
* Subscription (Non-EVM): 166.67 CUs
* Notification (EVM): 83.33 CUs
* Notification (Non-EVM): 416.67 CUs

See [Usage & Limits](/reference/websockets/usage-limits) for the full CU cost
table.

## Resources

* [Ankr Documentation](https://www.ankr.com/docs/)